The present invention relates to an air bag apparatus to be developed into a cabin compartment of a vehicle through a vehicle body panel and a garnish.
An air bag apparatus for use with a vehicle is proposed, which is interposed between a vehicle body panel and a garnish and which permits the development of the air bag in the cabin compartment of the vehicle through a clearance formed forcibly between the vehicle body panel and the garnish due to the expansion pressure applied to the air bag to be developed upon operation of the air bag. Japanese Patent Laid-Open Publication Nos. 9-254,736 and 11-321,520 disclose each an air bag apparatus interposed between a vehicle body panel, including a roof side rail or a pillar, and the garnish mounted on the vehicle body panel with a holding device. The holding device mounted on and fixed to the garnish is inserted into a mounting hole formed in the vehicle body panel and an engagement portion formed in the holding device is allowed to come into abutment with a peripheral edge portion of the mounting hole, thereby preventing the holding device from coming off from the mounting hole. Further, the holding device is engaged with the mounting hole in an ordinary occasion in a state in which the garnish is disposed in the vicinity of the vehicle body panel, and the garnish can be displaced to some extent in the direction in which it is pulled out and released from the mounting hole, so as to be separated apart from the vehicle body panel upon receipt of the expansion pressure of the air bag.
The garnish of such a conventional air bag apparatus is structured, however, that it cannot be detached from the vehicle body panel simply by changing the depth of insertion of the garnish into the mounting hole formed in the vehicle body, after the garnish has once been mounted on the vehicle body panel, that is, after the holding device has once been mounted on the vehicle body panel, because the holding device cannot be detached from the vehicle body panel. Therefore, in order to detach the garnish from the vehicle body panel, for example, upon maintenance or exchanges of the air bag apparatus, the holding device has to be broken so that it cannot be reused.
Therefore, the present invention has been completed with the above situation involved in the conventional air bag apparatuses of the type as described above and has the object to provide an air bag apparatus that can assume a given mounted state in which the garnish for the air bag apparatus is located in the vicinity of the vehicle body panel and a separate state in which it is separated from the vehicle body panel to some extent. Further, the air bag apparatus enables the holding device to be reused upon attachment or detachment of the garnish to or from the vehicle body panel.
In order to achieve the above object, the present invention provides an air bag apparatus as claimed in claim 1, in which the air bag apparatus comprises an air bag disposed at a cabin compartment side of a vehicle body panel, a garnish disposed covering the air bag from the cabin compartment side, and a holding device disposed to hold the garnish so as to assume a first posture in which the garnish is located in a given mounted state in the vicinity of the vehicle body panel and a second posture in which a clearance through which the air bag can pass is formed between the garnish and the vehicle body panel in response to expansion pressure of the air bag, and in which the air bag is disposed expanding into the cabin compartment side from the clearance; wherein the holding device comprises a pin member and a grommet member, the pin member includes a first mounting engagement portion at which the pin member is detachably engaged with the garnish and a leg portion extending integrally from the first mounting engagement portion, and the grommet member includes a cylindrical portion disposed receiving the leg portion and a second mounting engagement portion formed integrally with the cylindrical portion and mountable on the vehicle body panel; wherein the leg portion includes a first engagement claw and a second engagement claw disposed at a relationship spaced apart in an axial direction of the leg portion; wherein the cylindrical portion includes a first engagement portion engageable with the first engagement claw of the leg portion in a state in which the leg portion is inserted deeply to assume the first posture, thereby preventing the leg portion from coming off from the cylindrical portion; wherein the cylindrical portion includes a second engagement portion engageable with the second engagement claw of the leg portion in a state in which the leg portion is inserted shallowly to assume the second posture, thereby preventing the leg portion from coming off from the cylindrical portion; wherein a force of engagement of the first engagement claw with the first engagement portion is set to become smaller than a force of engagement of the second engagement claw with the second engagement portion, and the engagement of the first engagement claw with the first engagement portion is released upon receipt of a force of separating the garnish apart from the vehicle body panel due to an expansion pressure on operation of the air bag apparatus while maintaining the second posture by engagement of the second engagement claw with the second engagement portion; and wherein the second engagement claw is detachably engaged with the second engagement portion.
According to the above embodiment, in an ordinary occasion, the leg portion of the pin member is situated in the first posture in which it is inserted deeply into the cylindrical portion of the grommet member and the garnish assumes a given (ordinary) mounted state in the vicinity of the vehicle body panel, and this first posture can be held by engaging the first engagement claw with the first engagement portion. As the pin member receives the external force in the direction in which it is being pulled out or released from the grommet member due to the force of the expansion pressure upon operation of the air bag apparatus, that is, upon development of the air bag, the engagement of the first engagement claw with the first engagement portion is released assuming the second posture in which the leg portion is inserted shallowly into the cylindrical portion and this second posture is maintained by engaging the second engagement claw with the second engagement portion. The second posture corresponds to the state in which a clearance is formed between the garnish and the vehicle body panel through which the air bag can pass, and the air bag is eventually developed into the cabin compartment of the vehicle through this clearance.
When the garnish is to be detached, the engagement of the second engagement claw with the second engagement portion is released and the pin member is then pulled out thoroughly from the grommet member. The pin member that has once been pulled out, however, can also be re-used for mounting the garnish on the vehicle body panel again, together with the grommet member mounted on the vehicle body panel. Preferred modes are described in claims 2 et seq on the basis of the above embodiment as a premise.
The invention as described in claim 1 provides an air bag apparatus with an air bag of a structure in which the air bag is developed through a clearance formed between the vehicle body panel and the garnish. In this structure, the state of mounting the garnish on the vehicle body panel can be changed between a closely mounted state and a clearance-formed state. Moreover, the garnish can be detached from the vehicle body panel by pulling the pin member out from the grommet member. In addition, the pin member once pulled out can be used again, together with the grommet member mounted on the vehicle body panel.
The invention as described in claim 2 provides a specific mode of releasing the engagement of the second engagement claw with the second engagement portion. In particular, this mode is directed to the way of releasing the engagement of the second engagement claw with the second engagement portion by utilizing the action in the direction crossing the direction of pulling the pin member out from the grommet member, such as the action of rotation, so that this mode is also preferred from the point of view of preventing an occurrence of the accident that the second engagement claw is disengaged from the second engagement portion in a careless manner.
In accordance with the present invention as described in claim 3, the second engagement claw can be disengaged from the second engagement portion by utilizing the elastic transformation of the second engagement claw and the pressing portion.
In accordance with the present invention as described in claim 4, there is provided a specific structure of each of the engagement claws with each of the engagement portions and a specific way of disengagement of the second engagement claw with the second engagement portion. In particular, the second engagement claw is gradually transformed elastically toward the inside in the radial direction of the cylindrical portion without difficulty by means of an inclining face formed on the pressing portion, in the process of pulling the pin member out from the grommet member.
The invention as described in claim 5 can preferably prevent the rotation of the second engagement claw relative to the pressing portion in a careless manner, thereby ensuring the sure maintenance of the second posture.
Further, the invention as described in claim 6 is preferred from the point of view of ensuring the maintenance of the second posture by engaging the second engagement claw with the second engagement portion for sure upon transferring the air bag from the first posture to the second posture by means of the expansion of the air bag.
Moreover, the invention as described in claim 7 is preferred in that the attachment and detachment of the pin member to and from the garnish can be effected with ease by utilizing sliding movement.
The invention as described in claim 8 can provide a specific structure that allows an easy attachment and detachment of the pin member to and from the garnish by utilizing the sliding movement.
In accordance with the invention as described in claim 9, it is preferred to render the leg portion more lightweight and higher in rigidity.
The invention as described in claim 10 presents the advantage that a careless rotation of the grommet member with respect to the vehicle body panel can be prevented when it is attempted to rotate the pin member relative to the grommet member.
In accordance with the invention as described in claim 11, it is preferred to automatically assume a state in which the rotation of the grommet relative to the vehicle body panel can be restricted, simply by inserting the cylindrical portion into the mounting hole of the vehicle body panel.
Further, in accordance with the invention as described in claim 12, the grommet member can be automatically fixed to the vehicle body panel simply by inserting the cylindrical portion of the grommet member into the mounting hole of the vehicle body panel.
The invention as described in claim 13 offers the advantage that the insertion of the pin member into the grommet member deeper to a predetermined position can be prevented for sure.
The invention as described in claim 14 can surely set the action of engagement of the first engagement claw to be smaller than the action of engagement of the second engagement claw.
In addition, the invention as claimed in claim 15 is preferred in that the pin member and the grommet member can be formed in a lightweight and less expensive manner.